There are many systems available for mounting PV modules to building structures, such as a roof. These systems serve as a rigid interconnection element between a roof and a PV module to hold the modules in place and resist the forces of gravity and wind.
Some traditional mounting systems consist of rows of rail structures attached to the roof in columns or rows, with module clamps used to attach the PV modules to these rail structures. More recently, San Rafael-based Zep Solar pioneered the use of “rail-free” systems, where the module frames themselves are sufficiently rigid to function as the rails of a PV mounting system. By utilizing the inherent rigidity of module frames as part of the PV mounting system, system part counts and costs of PV mounting systems were significantly reduced while installation time and overall aesthetics were improved. Most rail-free systems, rely on PV module supports which connect to each module frame at various points around the array—typically at least four points on each module. These supports are in turn attached to the roof (via a flashing), most typically into a roof rafter, although they can also be attached to the roof deck.
Both traditional rail mounting systems and rail-free systems typically use mechanical links to link together PV modules in north-south and east-west connections. Due to the variable nature of the PV module arrays, rail structures and/or roof rafters, the desired or required location of mechanical links sometimes conflicts with the desired or required location of the clamps used to attach the PV modules to rail structures or supports used to connect the module frame to the roof and/or roof rafters (in the case of rail-free systems).
One current solution to these conflicts is a specially-designed supporting foot that interfaces between the PV module and the rail or roof rafters, where the base of the foot is designed with sufficient length so as to allow the supporting foot to attach to the desired location (e.g., the predefined location of rail structures or roof rafters) and couple with the PV modules outside of the desired location of the mechanical links adjoining the PV modules. While this allows the mechanical links and the supports to be connected at desired locations, it has a number of limitations. First, the additional length between the connection point to the rail strucures or the roof rafters and the PV modules increases the magnitude of the torque applied to the components, making them more susceptible to failure. Second, the necessary additional length of the supporting foot requires additional material and increases the cost per part.
Another current solution to the conflicts is a specially-designed assembly that both links PV modules in the north-south and east-west directions and couples the modules to the underlying rail structures or roof rafters. For example, so-called “hybrid interlocks” that provide a way to resolve conflicts that may occur between “interlocks” that link PV modules and “leveling feet” that couple the PV modules to roof rafters are described in U.S. Patent Application Publication No. 2012/0234378, filed Dec. 9, 2011 and entitled “Pivot-Fit Connection Apparatus and System for Photovoltaic Arrays.” While these “hybrid interlocks” can resolve the conflicts, they too have limitations. First, the parts of such assemblies are complex, and require additional material, greatly increasing the cost per part. Second, such assemblies are typically only applicable to situations where the conflicts occur, introducing complexities in the installation of PV arrays that result in increased time and cost for installation. Furthermore, such assemblies also require installers to bring more parts and associated tools to installation sites in case such an assembly is needed.
Accordingly, there is a need for a more cost-effective solution for resolving conflicts between the mechanical linkages joining PV modules and the supporting members mounting the PV modules to the roof